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Water Division 4: the Gunnison
Water Division 4 is the Gunnison basin, plus the San Miguel, the Little Dolores, and the Dolores north of the Township 45 North line. C.R.S. § 37-92-201(1)(d)
It holds 22,396 decreed water-right records (13% of the state), including the largest storage right in any division. Its water court sits in three courthouses, Delta, Gunnison and Montrose, and its division engineer is in Montrose.
Division 4 at a glance
| Measure | Division 4 | Among the seven |
|---|---|---|
| Decreed water-right records | 22,396 | third most, 13% of the state |
| Records with an absolute amount | 18,662 | 83% of the division |
| Records that are conditional only | 1,496 | rank 3 of 7 |
| Distinct structures (WDIDs) | 17,452 | rank 3 of 7 |
| Well permit records | 25,570 | sixth most, 4% of the state |
| Ditch priorities dated before statehood (Aug. 1, 1876) | 45 | of 5,984 ditch priorities |
| Calls in effect, Oct. 2026 | 16 | dated snapshot, see below |
Counts pulled from the Colorado Division of Water Resources on October 16, 2026 DWR net amounts DWR well permits. A "record" is one decreed priority, so a ditch with three decrees counts three times; a well permit record is not a water right (see well permit vs. water right).
Big reservoirs, power plants, and a river split in two
Division 4 is a surface-water division. Wells are only 9% of its records (2,027); ditches, reservoirs and springs carry most of the rest. At the top of that system is Blue Mesa Reservoir, decreed for 1,063,457 acre-feet, the largest absolute storage right in any Colorado division. Its three largest flow rights are all decreed for power generation: Crystal Power Plant (3,000 cfs), Morrow Point Power Plant (2,950 cfs), Blue Mesa Power Plant (2,500 cfs).
Federal reserved rights show up plainly in the record too: 2,908 records here carry the federal reserved use code, one of the most common uses in the division. They sit alongside the familiar irrigation and stock rights in the same DWR tabulation of decreed rights.
The Dolores is the one river the statute divides between two divisions. North of the Township 45 North line it is in Division 4; south of it, the Dolores and its tributaries belong to Division 7. Ditch priorities start later here than on the Front Range: the oldest ditch priority still decreed absolute is the SEVENTY FIVE DITCH on the Gunnison River, appropriated May 10, 1875, and only 45 ditch priorities predate statehood.
What the statute puts in Division 4
Division 4: Division 4 consists of all lands in the state of Colorado in the drainage basins of the Gunnison river and all of its tributaries, the Little Dolores river, the San Miguel river, and that portion of the Dolores river and its tributaries north of the north township line of Township 45 North, New Mexico Principal Meridian.
The oldest ditch priorities in Division 4
The five most senior ditch priorities in the division that still carry an absolute amount, ranked by DWR's administration number, one per structure. Each name links to the record in DWR's own system.
| Structure | Source | Appropriated | Net absolute | Decreed uses |
|---|---|---|---|---|
| SEVENTY FIVE DITCH | GUNNISON RIVER | May 10, 1875 | 14 cfs | Irrigation, Municipal, Recreation, Fishery, Fire, Domestic, Stock, Augmentation |
| JOHN B OUTCALT NO 1 D | GUNNISON RIVER | Jul. 31, 1875 | 3.3 cfs | Irrigation |
| OLD AGENCY DITCH | UNCOMPAHGRE RIVER | Aug. 1, 1875 | 7.5 cfs | Irrigation |
| F S WILLIAM D NO 1 | FRIENDS CREEK | Aug. 15, 1875 | 0.71 cfs | Irrigation |
| VIDAL BROS NO 1 DITCH | OHIO CREEK | Apr. 1, 1876 | 2.95 cfs | Irrigation |
Ditches only: ranked across every structure type, the top of the list is taken by well and compact-accounting records dated earlier than any ditch (in some divisions, wells dated Dec. 31, 1850). Priority, not size, decides who is curtailed first in a call; read prior appropriation for why.
The largest decreed rights
Ranked by net absolute amount, flow and storage separately because cubic feet per second and acre-feet measure different things. Big flow numbers often belong to power plants, whitewater parks and minimum streamflow rights; the decreed uses column shows which.
Flow rights (cfs)
| Structure | Source | Appropriated | Net absolute | Decreed uses |
|---|---|---|---|---|
| CRYSTAL POWER PLANT | GUNNISON RIVER | Nov. 13, 1957 | 3,000 cfs | Power generation |
| MORROW POINT POWER PLANT | GUNNISON RIVER | Feb. 2, 1959 | 2,950 cfs | Power generation |
| BLUE MESA POWER PLANT | GUNNISON RIVER | Nov. 13, 1957 | 2,500 cfs | Power generation |
| GUNNISON RIVER WHITEWATER COURSE | GUNNISON RIVER | Oct. 20, 1998 | 1,200 cfs | Recreation |
| GUNNISON TUNNEL AND SOUTH CANAL | GUNNISON RIVER | Jun. 1, 1901 | 1,175 cfs | Irrigation, Municipal, Stock |
Storage rights (acre-feet)
| Structure | Source | Appropriated | Net absolute | Decreed uses |
|---|---|---|---|---|
| BLUE MESA RESERVOIR | GUNNISON RIVER | Nov. 13, 1957 | 1,063,457 AF | Irrigation, Municipal, Industrial, Recreation, Fishery, Domestic, Stock, Augmentation, Power generation |
| MORROW POINT RESERVOIR | GUNNISON RIVER | Nov. 13, 1957 | 119,053 AF | Irrigation, Municipal, Industrial, Recreation, Fishery, Domestic, Stock, Power generation |
| TAYLOR PARK RESERVOIR | TAYLOR RIVER | Aug. 3, 1904 | 111,230 AF | Irrigation |
| RIDGWAY RESERVOIR TRI CT | UNCOMPAHGRE RIVER | Nov. 16, 1956 | 84,602 AF | Irrigation, Municipal, Industrial, Recreation, Fishery, Domestic, Stock, Augmentation, Power generation, Other |
| RAINBOW LAKE RESERVOIR | WILLOW CREEK | Jul. 21, 1897 | 74,521 AF | Irrigation |
A structure's net absolute amount is DWR's sum of its decreed transactions; the decree itself, read through how to read a decree, controls what the right can actually divert and when.
What the water is decreed for, and what diverts it
| Decreed use | Records carrying it | Share |
|---|---|---|
| Irrigation | 11,809 | 53% |
| Stock | 7,847 | 35% |
| Domestic | 5,766 | 26% |
| Wildlife | 3,333 | 15% |
| Federal reserved | 2,908 | 13% |
| Fishery | 2,337 | 10% |
| Structure type | Records | Share |
|---|---|---|
| Ditch | 6,912 | 31% |
| Reservoir | 6,104 | 27% |
| Spring | 5,550 | 25% |
| Well | 2,027 | 9% |
| Pump | 567 | 3% |
| Pipeline | 534 | 2% |
A record can carry several uses, so the shares add up to more than 100%. Use codes are DWR's own, as published with the net amounts data.
Streams, water districts and counties
Sources with the most decreed records: Gunnison River (1,089); San Miguel River (818); North Fork Gunnison River (697); Uncompahgre River (644); Leroux Creek (569); Horsefly Creek (553). "Groundwater:" entries are wells drawing on that stream's alluvium or on a named aquifer.
| Water district | Decreed records |
|---|---|
| 28 | 1,901 |
| 40 | 7,032 |
| 41 | 1,254 |
| 42 | 879 |
| 59 | 2,951 |
| 60 | 3,349 |
| 61 | 211 |
| 62 | 2,283 |
| 63 | 678 |
| 68 | 1,583 |
| 73 | 275 |
The district number is the first two digits of every WDID in it, and each district is typically covered by a water commissioner. Districts are numbered across the state, not within the division, which is why the numbers here are not consecutive.
Counties with the most records here: Gunnison (6,604); Delta (5,342); Montrose (3,324); San Miguel (2,093); Mesa (1,942); Ouray (1,576); Saguache (890); Hinsdale (608). Division lines follow drainage, so a county can appear in two divisions; place a parcel with the DWR map viewer rather than by county.
Calls in effect on October 16, 2026
When this page's data was pulled, DWR listed 16 active administrative records in Division 4 (15 calls, 1 nonconsumptive call). The 5 with the oldest priority dates are below, oldest priority first; an older calling priority curtails more junior rights on that stream.
| Stream | Calling right | Priority date | Call set |
|---|---|---|---|
| RAZOR CREEK | KENNEDY DITCH NO 1 | Mar. 15, 1878 | Apr. 10, 2026 |
| SPRING CREEK | SPRING CREEK VALLEY D | Jun. 13, 1883 | May 5, 2026 |
| LEROUX CREEK | CURRANT CREEK DITCH | Aug. 4, 1883 | Jun. 29, 2026 |
| DIRTY GEORGE CREEK | WEST DITCH | Dec. 20, 1883 | May 27, 2026 |
| TONGUE CREEK | PARK DITCH | May 3, 1884 | May 27, 2026 |
Water court, water clerk and division engineer
- Water court: Delta County Courthouse, Delta; Gunnison County Courthouse, Gunnison; and Montrose County Courthouse, Montrose Colorado Judicial Branch · Oct. 2026. Applications are heard by the Division 4 water judge, designated each year by the Colorado Supreme Court C.R.S. § 37-92-203(2). The court's own page publishes the monthly resume of applications Water Division 4.
- Water clerk: in the office of the clerk of the district court, Montrose County C.R.S. § 37-92-204(1)(b).
- Division engineer: office in Montrose C.R.S. § 37-92-202(1)(b). The division engineer administers rights on the ground and places curtailment orders.
Interstate compacts codified in Title 37 that govern this division's rivers:
- Colorado River Compact C.R.S. title 37, article 61
- Upper Colorado River Compact C.R.S. title 37, article 62
Each compact is an agreement between states, ratified by the General Assembly and codified in the article cited. See the Colorado River Compact for how that works on the largest of them.
The other six divisions
- Division 1: South Platte (58,418 decreed records)
- Division 2: Arkansas (20,249 decreed records)
- Division 3: Rio Grande (18,451 decreed records)
- Division 5: Colorado (27,726 decreed records)
- Division 6: Yampa, White and North Platte (17,878 decreed records)
- Division 7: San Juan and Dolores (8,081 decreed records)
All seven side by side, with the map, are on Colorado's seven water divisions.
Common questions
Where is the water court for Division 4?
Division 4 is the one division whose court sits in three places: the Delta, Gunnison and Montrose county courthouses. The water clerk keeps filings in the Montrose County district court clerk's office (C.R.S. § 37-92-204(1)(b)), and the division engineer's office is in Montrose.
What is the largest water right in Division 4?
Blue Mesa Reservoir, decreed for 1,063,457 acre-feet of storage, the largest absolute storage right in any Colorado division as recorded by DWR on October 16, 2026. The largest flow rights are the power plants below it on the Gunnison.
Is the Dolores River in Division 4 or Division 7?
Both. C.R.S. § 37-92-201(1)(d) puts the Dolores and its tributaries north of the north township line of Township 45 North, New Mexico Principal Meridian, in Division 4; § 37-92-201(1)(g) puts the part south of that line in Division 7.
Which counties are in Water Division 4?
By number of decreed records: Gunnison, Delta, Montrose, San Miguel, Mesa, Ouray. Mesa and Saguache counties are split with other divisions, so place a specific parcel with the DWR Map Viewer.